Messages in this thread Patch in this message | | | Subject | Re: [PATCH v2 2/5] staging: r8188eu: cast to restricted __be32 | From | Larry Finger <> | Date | Fri, 20 Aug 2021 16:44:49 -0500 |
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On 8/19/21 3:17 AM, Aakash Hemadri wrote: > Fix sparse warning: >> rtw_br_ext.c:836:54: warning: cast to restricted __be32 > > Unnecessary double cast, remove them. > > Signed-off-by: Aakash Hemadri <aakashhemadri123@gmail.com> > --- > drivers/staging/r8188eu/core/rtw_br_ext.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/staging/r8188eu/core/rtw_br_ext.c b/drivers/staging/r8188eu/core/rtw_br_ext.c > index 404fa8904e47..6a0462ce6230 100644 > --- a/drivers/staging/r8188eu/core/rtw_br_ext.c > +++ b/drivers/staging/r8188eu/core/rtw_br_ext.c > @@ -671,7 +671,7 @@ void dhcp_flag_bcast(struct adapter *priv, struct sk_buff *skb) > (udph->dest == __constant_htons(SERVER_PORT))) { /* DHCP request */ > struct dhcpMessage *dhcph = > (struct dhcpMessage *)((size_t)udph + sizeof(struct udphdr)); > - u32 cookie = be32_to_cpu((__be32)dhcph->cookie); > + u32 cookie = dhcph->cookie; > > if (cookie == DHCP_MAGIC) { /* match magic word */ > if (!(dhcph->flags & htons(BROADCAST_FLAG))) { >
This patch is wrong. All the documentation I could find tells me that the multi-byte entries in dhcph are big-endian, thus the new line should read:
u32 cookie = be32_to_cpu(dhcph->cookie); combined with:
@@ -649,7 +650,7 @@ struct dhcpMessage { u_int8_t chaddr[16]; u_int8_t sname[64]; u_int8_t file[128]; - u_int32_t cookie; + __be32 cookie; u_int8_t options[308]; /* 312 - cookie */ };
The old code was, in fact, correct, but not in a way that satisfied Sparse. Larry
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